UTMB Fertility Center Services
in vitro Fertilization (IVF)
in vitro fertilization is a process by which, in the laboratory, eggs and sperm obtained from the infertile couple are combined in a culture dish in an incubator. When fertilization takes place under these controlled conditions, one or more eggs are transferred into the woman's uterus, where it is hoped that the egg will implant itself, grow, and result in a normal pregnancy.
The in vitro fertilization program is a team effort involving reproductive endocrinologists, nurses, embryologists, andrologists, and anesthesiologists. Care is provided not by a single physician, but by a team of physicians and nurses.
When Should a Couple Consider IVF?
Infertility has not responed to conventional methods of treatment and one or more of the following factors are involved:
- Unsuccessful tubal surgery
- Uncorrectable tubal obstruction
- Low sperm count
- Poor cervical mucus
- Sperm antibodies
- No reason for infertility has been found after thorough evaluation, and the couple has failed to conceive after the GIFT procedure
- The woman has at least one functional ovary and a functional uterus
Steps in the IVF Procedure
1) Fertility drug injections to induce multiple follicular development
Early in the menstrual cycle the woman is given injections of a fertility drug such as Bravelle®, Repronex®, Follistim®, or Gonal-F® to stimulate the ovaries to develop more than one egg. Two to four fertilized eggs are transferred to the uterus to increase the chances of successful pregnancy. Fertilization and transfer of more than one egg increases the likelihood of successful pregnancy; at the same time, it increases the chance of twinning and other multiple pregnancies. However, in most instances, only one egg implants and develops. If more than four eggs are fertilized, the rest of the eggs are frozen and preserved for transfer in subsequent cycles.
2) Ultrasound monitoring
Success with in vitro fertilization is closely related to harvesting the eggs at the right time. Hormone levels in the blood are monitored daily after the first four or five days of fertility-drug injections; as the follicles grow, they are monitored through a series of ultrasound examinations. Ultrasonography is a procedure that uses high-frequency sound waves to provide a picture of the ovaries and the growing follicles.
Just before ovulation, when the size of the follicles and the level of the hormone estradiol are optimal, an injection of another hormone (Human Chorionic Gonadotropin) is given. This hormone will cause the eggs to be released 36 hours after it is injected, and retrieval is scheduled for that time.
3) Egg retrieval
Eggs can be taken from the ovaries either by transvaginal ultrasound-guided retrieval or laparoscopic techniques. The technique used depends on the accessibility of the ovaries.
Transvaginal ultrasound-guided retrieval is usually performed under conscious sedation. The ultrasound probe is introduced into the vagina and the follicles are located. Then, the aspiration needle is passed through a guide into the pelvic and the follicular fluid is aspirated.
In laparoscopy, a laparoscope is introduced through a small incision just below the navel to visualize the ovaries. Another instrument, which is used to position the ovaries and hold them steady, is introduced through a second, smaller incision made in the lower abdomen. A needle, passed through the laparoscope, aspirates (draws out) the follicular fluid, which contains the eggs.
The fluid aspirated from the follicles containing the eggs is transferred to a special laboratory where the eggs are identified under a microscope, transferred to a special culture medium, and placed in an incubator.
A sperm specimen is obtained from the husband at the time of egg retrieval. Another sperm specimen, obtained and frozen one week earlier, will be used if the sperm sample obtained on the day of laparoscopy is not optimal.
The egg and the sperm are combined in a culture dish, and the dish is placed in an incubator for 48 hours. This process of fertilization outside the human body is referred to as in vitro fertilization.
Even under normal physiological conditions, fertilization does not always occur when a sperm and egg meet, and sometimes an egg is fertilized but does not develop further. When fertilization and development do occur, the eggs are transferred to the uterus three to five days after egg retrieval.
4) Egg transfer
The fertilized egg is transferred to the uterus by way of a small plastic catheter; the procedure requires no anesthesia. Progesterone, a hormone that prepares the lining of the uterus for implantation, will be administered daily (after transfer) either by injection, vaginal suppositories, or as a gel (Crinone gel®).
5) Obstetrical Care
A test for pregnancy is performed about two weeks after the fertilized eggs are transferred to the uterus. If the test is positive, progesterone treatment is continued for another eight weeks. Prenatal care after in vitro fertilization is the same as for any other pregnancy and may be provided by your obstetrician.
IVF Time Commitment
- Consultation visit
- Brief visits for five days or more for ovulation-inducing injections (injections may be administered by your regular physician, or your husband could be trained to give these injections)
- Visit for blood samples and ultrasound examination every morning for three to seven days before egg retrieval
- One day for transvaginal ultrasound aspiration
- One day in the clinic for egg transfer
It is important for couples to understand that IVF is attempted only when all conventional methods of treatment have failed. The probability of pregnancy in any attempt of IVF is approximately 40 percent. This average may be higher in women under 30 years of age, and lower in women over 40. The average number of attempts is three. Couples who achieve pregnancy without medical intervention do so only after an average of three months. in vitro fertilization is a time-consuming, expensive process, but it is the only option for women with damaged tubes and for those who have exhausted all other treatments.
Cryopreservation-Frozen Embryo Transfer (FET)
In the majority of IVF or GIFT cycles, stimulation of the ovaries by fertility drugs results in development of several follicles and retrieval of multiple eggs. Usually, only three to four eggs are transferred immediately in that cycle. The rest of the fertilized eggs are frozen and stored in a special freezer. With the current programmable freezing method, 60 to 80 percent of embryos are viable after thawing. One of the advantages of Frozen Embryo Transfer (FET) is that the transfer will occur in a natural ovulatory cycle. When stimulating drugs are not used, endometrial receptivity is improved and implantation is more likely.
Oocyte Donation Program
Most donor eggs are obtained from anonymous donors. IVF with donor eggs has the highest pregnancy rate since the egg donors are always less than 35 years old. The alternate source of eggs is close friends or relatives who are willing to undergo ovarian stimulation and egg retrieval for the sole purpose of donating eggs. Oocyte donation presents many medical and ethical questions which should be considered before the oocyte donation procedure is initiated.
Microsurgical Epididymal Sperm Aspiration (MESA)
Possible indications for this procedure include congenital absences of the vas deferens or failed vasectomy reversal. Sperm aspirated from the most proximal regions of epididymis are the most recently produced and have the best motility. This sperm is then used for ICSI and IVF or GIFT procedures.
Intracytoplasmic Sperm Injection (ICSI)
This technique facilitates laboratory fertilization via the microinjection of one sperm inside the egg. Sperm with a low motility can thus be helped to penetrate the shell around the egg (zona pellucida) and achieve sperm-egg fusion. A single living sperm, even with poor motility, can fertilize the egg. Only the microinjection aspect of this technique, done in the laboratory, differs from conventional IVF.
In ICSI, the woman must follow the same procedure as for IVF with ovarion stimulation and ovum pick up, followed by laboratory fertilization and embryo transfer after 48 hours.